DRPC-230-ULT5 Embedded System
Page 101
NOTE:
The following discussion applies to DOS. Contact IEI support or visit
the IEI website for drivers for other operating systems.
The Watchdog Timer is a hardware-based timer that attempts to restart the system when it
stops working. The system may stop working because of external EMI or software bugs.
The Watchdog Timer ensures that standalone systems like ATMs will automatically
attempt to restart in the case of system problems.
A BIOS function call (INT 15H) is used to control the Watchdog Timer.
INT 15H:
AH – 6FH Sub-function:
AL – 2:
Sets the Watchdog Timer’s period.
BL:
Time-out value (Its unit-second is dependent on the item “Watchdog
Timer unit select” in CMOS setup).
Table D-1: AH-6FH Sub-function
Call sub-function 2 to set the time-out period of Watchdog Timer first. If the time-out value
is not zero, the Watchdog Timer starts counting down. When the timer value reaches zero,
the system resets. To ensure that this reset condition does not occur, calling sub-function
2 must periodically refresh the Watchdog Timer. However, the watchdog timer is disabled
if the time-out value is set to zero.
A tolerance of at least 10% must be maintained to avoid unknown routines within the
operating system (DOS), such as disk I/O that can be very time-consuming.
Содержание DRPC-230-ULT5 Series
Страница 11: ...DRPC 230 ULT5 Embedded System Page 1 Chapter 1 1 Introduction ...
Страница 19: ...DRPC 230 ULT5 Embedded System Page 9 1 7 2 DRPC 230 ULT5 i5 8G Figure 1 5 DRPC 230 ULT5 i5 8G Dimensions mm ...
Страница 20: ...DRPC 230 ULT5 Embedded System Page 10 Chapter 2 2 Unpacking ...
Страница 25: ...DRPC 230 ULT5 Embedded System Page 15 Chapter 3 3 Installation ...
Страница 46: ...DRPC 230 ULT5 Embedded System Page 36 Chapter 4 4 Troubleshooting and Maintenance ...
Страница 51: ...DRPC 230 ULT5 Embedded System Page 41 Chapter 5 5 BIOS ...
Страница 91: ...DRPC 230 ULT5 Embedded System Page 81 Chapter 6 6 Interface Connectors ...
Страница 97: ...DRPC 230 ULT5 Embedded System Page 87 Appendix A A Regulatory Compliance ...
Страница 102: ...DRPC 230 ULT5 Embedded System Page 92 Appendix B B Safety Precautions ...
Страница 107: ...DRPC 230 ULT5 Embedded System Page 97 Appendix C C Digital I O Interface ...
Страница 110: ...DRPC 230 ULT5 Embedded System Page 100 Appendix D D Watchdog Timer ...
Страница 113: ...DRPC 230 ULT5 Embedded System Page 103 Appendix E E Error Beep Code ...
Страница 115: ...DRPC 230 ULT5 Embedded System Page 105 Appendix F F Hazardous Materials Disclosure ...